How to Grow Chrysanthemums

Chrysanthemums (Chrysanthemum spp.) take center stage in fall, just as most annuals and perennials are closing up shop for the season. These extravagant flowers have disc-like blooms in a variety of bright hues. Most commonly, you’ll find them in grocery stores and nurseries in August and September in shades of white, orange, yellow or rust, but they’re also available in pinks and purples.

Chrysanthemums are from China, where they’ve been cultivated since at least 500 B.C. American gardeners have enjoyed chrysanthemums for only the last 60 years or so, although they were introduced to Europe in the 1700s. The Swedish botanist, Linnaeus, gave chrysanthemums their name in the mid-1700s, which in Greek means “gold flower.”

Most gardeners grow chrysanthemums as annuals. If you’d like to grow them this way, simply pop them in the ground or in pots in late summer or early fall. Select a sunny location away from street lights, since chrysanthemums need several hours of darkness at night to flower properly. Water chrysanthemums frequently so the soil stays moist 1-inch beneath the surface. Dig the plants up and discard them after the first heavy freeze.

Growing Perennial Chrysanthemums

If tossing chrysanthemums on the compost heap seems like a waste, take heart. In U.S. Department of Agriculture plant hardiness zones 5 through 9, these cheery flowers can be grown as perennials. To grow chrysanthemums year-round, select varieties adapted to your area. Not all chrysanthemums are reliably winter hardy in the north, so it’s important to get the right kind.

Choose a site that gets full sun and has well-draining soil, since chrysanthemums don’t tolerate wet feet. Amend the soil to a depth of 8 to 12 inches with compost or manure. In soggy soils, try growing chrysanthemums in pots or raised beds.

Plant nursery transplants outdoors in the spring, spacing them 15 to 24 inches apart. Once the plants stand 6 inches tall, pinch off the tips to the first leaves. Repeat this pinching several times during the summer to keep the plants compact and encourage more blooming. Stop pinching them, though, by early August or you’ll destroy the fall flower display. Remember, chrysanthemums really start blooming when night time temperatures cool and the length of night darkness increases to 12 hours. In most areas, they’re at their best in September and October. Drought and high heat reduce flowering.

Fertilize chrysanthemums in early spring when new growth appears with ¼ cup of 10-10-10 fertilizer. Fertilize them again mid-summer, but don’t fertilize them after August. Chrysanthemums need consistent moisture, so water as often as needed to keep the soil slightly moist, but not soggy.

Chrysanthemums can tolerate light freezes which is one reason they’re so beloved in the fall. They don’t, however, handle hard freezes. If you live in zone five, plant chrysanthemums in a protected area, such as next to the house, and cover them in the fall with 3 to 4 inches of wood chip mulch to protect their roots. Leave the dried plant material standing over the winter because it provides additional insulation.

Divide perennial chrysanthemums every three to four years, as growth declines and the plants become crowded. Dig up the plants in early spring and cut them into three wedges. Cut off the inner portions of the wedges, because these parts are the oldest parts of the plant and are likely unproductive. Replant the divisions, spacing them 15 to 24 inches apart.

Chrysanthemum Pests and Problems

Chrysanthemums are subject to root rots and fungal leaf diseases. To minimize these problems, plant chrysanthemums in well-draining soil and space them so air circulates freely. Water the plants in the morning and use drip systems instead of overhead sprinklers, which tend to exacerbate fungal diseases.

Want to learn more about growing chrysanthemums?

Ryan Lee from Indiana University teaches about chrysanthemum care on YouTube.

Julie Christensen learned about gardening on her grandfather’s farm and mother’s vegetable garden in southern Idaho. Today, she lives and gardens on the high plains of Colorado. When she’s not digging in the dirt, Julie writes about food, education, parenting and gardening.